1. Field of the Invention
This invention relates generally to moorings for ocean going vessels. In particular, this invention relates to a portable dolphin system which is rapidly installable and retrievable for reuse.
2. Description of the Prior Art
In the prior art there are several marine structures which are designed to resist ship berthing loads. Driven pile clusters usually made of wood, concrete or steel are used to protect piers, docks and wharfs. The number of piles in a cluster ranges from 3 to 19. The driven pile cluster is suitable for soils such as dense sand or hard clays but is not suitable on soft sediments.
To resist large ship loads such as those resulting from oil tankers, cellular sheet pile walls filled with granular materials have been used. On mud or a soft clay sea floor, the piles must be driven to great depths to insure proper lateral resistance. In addition, the sheet pile wall cannot be driven into hard coral or rock.
A third type of dolphin is a closed box concrete caisson which is pre-fabricated, towed to a designated site and ballasted with sea water. For a permanent installation, a layer of gravel or crushed rock is placed on the sea floor prior to placement of the caisson. However, the concrete box caisson is very heavy and bulky.